Para-athletes covered a sprint-distance course featuring a 750 metre swim, 20 kilometre cycle and 5km run.

Norman crossed the line in a time of 1 hour, 9 min, 49sec, edging runner-up Lauren Steadman of Great Britain by just four seconds.

It means she remains undefeated in ITU competition since winning her first world title last year, also in Rotterdam.

Her accolades since then have included a gold medal at the Rio 2016 Paralympic Games and an ITU World Para-triathlon Series victory in Edmonton in July, though she also struggled with an injury at the beginning of the 2017 season.

“It was a lot harder than I was expecting, but it was good," said Norman.

"I’m very glad I didn’t give up.

“Coming back from injury in the spring, where I didn’t even know if I’d be able to race this, to win this is amazing.

"And to defend it here again, it was just so fun.”

Gwladys Lemoussu of France rounded off the podium positions in 1:12:19.

There was a fierce battle for gold between two Dutch competitors in the men's PTWC event.

Rio 2016 champion Jetze Plat and Paralympic silver medallist Geert Schipper secured a one-two for the host nation.

But Plat, the reigning world champion, managed to get the better of his fellow countryman once again after leading throughout the majority of the race.

The 26-year-old, who won the Gold Coast leg of the competition and the 2017 European Championships title, sealed a memorable campaign with victory in 1:02:18.

Schipper took second place in 1:04:27 while Joseph Townsend of Great Britain sealed bronze with his time of 1:10:37.

In the women’s equivalent, Australian Emily Tapp claimed victory.

First out of the water was Briton Jade Jones, but she was caught on the third lap of the cycle by Tapp, who failed to relinquish her advantage in the remainder of the race and won in 1:20:28.

Jones held on for second place in 1:21:26, finishing in front of Spaniard Eva Maria Moral Pedrero, who took third in 1:24:12.

Despite having to serve a ten-second penalty for an "irregular transition", Frenchman Alexis Hanquinquant dominated the men's PTS4 final, winning by over two minutes.

Leading out of the swim, his first transition caused the penalty and an addition to his time.

However, he managed to hold onto his lead after dominating the cycle and run to win in a time of 1:04:15.

Steven Crowley of Great Britain finished second in 1:06:52, while American Jamie Brown occupied third in 1:07:54.

Canada’s Stefan Daniel collected his second world title in three years in the men's PTS5 discipline.

His strength on the bike and run earned him the crown after Daniel left the swim over 30 seconds behind Great Britain’s George Peasgood.

However, the Canadian closed the gap on the first lap of the cycle to move into the lead, before extending his advantage in the closing stages to add to his 2015 world success in 1:01:20.

Spaniard Jairo Ruiz Lopez finished second in 1:03:21 while Chris Hammer of the US completed the podium positions in 1:03:44.